Sen. Mark Udall strode into his new Western Slope headquarters last week with a very specific target in mind: women.

In two of the first three television ads aired by his reelection campaign, Udall has hammered his opponent's conservative positions on abortion and past support for Colorado personhood initiatives, which would have changed the state's constitution to protect a person's rights from the point of conception.

Last week, the Supreme Court handed Udall a fresh talking point to motivate female voters, particularly the single women who are so critical for Udall's fellow Democrats in presidential elections but often stay home in midterm contests. It was the first issue he raised with the crowd after walking through the door.

"Five men made a decision for millions of American women," Udall said of the Supreme Court's decision in the Hobby Lobby case, which gave some employers the right to claim a religious exemption to the healthcare law's requirement of contraception coverage. "These are personal matters. These are intimate matters.... A judge, your boss, your congressman shouldn't be telling women what to do."

To keep the issue alive, Udall co-sponsored a legislative fix to the Hobby Lobby decision this week, and many of his endangered Democratic colleagues signed on.

Issues like abortion, personhood and birth control don't rank anywhere close to the top of the priority list for most female voters, but Udall and other vulnerable Democrats hope that a decisive number of women in hotly-contested states will find their arguments persuasive. Their push against the traditional midterm slump comes as the party faces the possibility of losing control of the Senate.

The Democratic Senatorial Campaign Committee is spending $60 million on the Bannock Street Project, aimed at raising turnout among women, Latino and African American voters to what might be seen in a presidential election year.

Though single women make up a growing share of the electorate — nearly 4.2 million became eligible to cast ballots since 2008 — their voting drops off dramatically in non-presidential years. In 2010, some 22 million fewer unmarried women voted than in 2008, according to a study by the Voter Participation Center and Lake Research Partners; 10 million fewer married women voted.

Colorado is a battle for looking like you're reasonable.— Floyd Ciruli, independent pollster and analyst

The national project, aimed at turning out voters in as many as 12 contested states, gets its name from the Denver street where Sen. Michael Bennet's campaign was headquartered in 2010 when he won women's votes by a double-digit margin en route to a victory of less than 2 percentage points overall. Colorado Democrats, along with Udall's campaign, have already hired 100 organizers with the goal of registering 40,000 new voters, many of them women.

The opportunities in Colorado are significant for both sides. Though Udall led his Republican opponent, Rep. Cory Gardner of Yuma, among women, 52% to 35%, in a Quinnipiac University poll earlier this year, 58% of women said they did not know enough about Gardner to offer an opinion. (By contrast, 19% of women said the same about Udall, a first-term senator.)

Udall has spared no opportunity to argue that Gardner is, as he said last week, "not in the mainstream — he's in the extreme, and he's running away from his record every chance he gets."

Yet this year remains a challenge for Democrats. President Obama's job approval ratings are mired in the low 40s here; though employment has rebounded recently, many voters are still uneasy about the economy. And polls show Republican voters are more energized.

Colorado Democrats have worked in recent years to draw in more socially moderate voters, taking advantage of the state Republican Party's move to the right. Those voters played a major role in defeating, by 3-1 margins, the 2008 and 2010 ballot initiatives defining personhood in Colorado's constitution.

Now that issue has returned in Democratic attacks on Gardner, who was closely identified with the ballot initiatives as a state lawmaker. Gardner renounced his support for the Colorado personhood language when he entered the race this year, a reversal he said he made after learning that the measures could restrict some forms of birth control. But the congressman has been hit with millions of dollars in attack ads highlighting the issue, aired both by Udall's campaign and outside groups like Planned Parenthood.

Udall's ads note that Gardner sponsored a 2007 state bill that would have made it a class 3 felony to perform an abortion except when the life of the mother was at risk, and allege that his support of Colorado personhood amounted to "an eight-year crusade to outlaw birth control" — a claim Gardner says is deceptive and untrue.

But the message has alarmed even some Republican voters like 28-year-old Leslie Coblentz of Fort Collins. "The ads are definitely persuasive," she said Friday, moments after watching Udall and Gardner work the parade route at the Greeley Stampede. "When you hear about women not being able to make their own decisions, it's a turnoff. That's why I'm not quite sure who I want to vote for, because I just don't know enough."

At the same time, many women said they didn't have a clear opinion of either Senate candidate and a number said they immediately hit the mute button when they saw the anti-Gardner ads.

"No offense, but I could care less," one Grand Junction woman replied when asked whether the spots had swayed her.

Perhaps the Democrats' biggest challenge is re-engaging voters like Mary Stockum, a 24-year-old music teacher from Greeley. Though she voted for Obama in 2012, she said this year's election "doesn't feel like a priority."

"It would be good to care about something that would have an effect on me and that would actually matter," Stockum said. "But right now I don't see it." Access to birth control, she said, "is not really on my mind."

The anti-Gardner ads seemed to invoke the most passionate response from conservatives like Sandy Peeso, 62, of Grand Junction, who said Democrats had been distorting the facts both in the Udall-Gardner race and after the Hobby Lobby decision.

"It really irritates me that the truth is not being said," said Peeso, who predicted a backlash that could bring out more conservative women this fall. "They are purposely not saying the truth to gain in this, quote, war on women."

Gardner has aggressively countered Udall's approach in recent weeks, calling for common forms of birth control to be sold over the counter. He also took the unusual step of airing an ad explaining why he changed his mind on the Colorado personhood initiative: "I learned more from listening to all of you."

Udall has suggested that Gardner's position change was disingenuous because he is still a co-sponsor of a federal bill that declares that the right to life begins at fertilization. But Gardner rejects Udall's characterization and said it "is a pro-life statement" that would not affect contraception. Gardner says Udall is trying to distract voters from the economy and the unpopularity of the federal healthcare law, which only 37% of state voters backed in the Quinnipiac poll this year.

"He's the social-issue warrior in this campaign, and I'm going to be focused on jobs, the economy and those issues that matter at the kitchen table," Gardner said.

Floyd Ciruli, an independent pollster and analyst, said Gardner had strengthened his position by switching his position on personhood, which he said was the candidate's greatest liability. "Painful," he said, "but a smart move."

Ultimately this year, Ciruli said, "Colorado is a battle for looking like you're reasonable."